Coal-scbeeet



UNITED STATES PATENT CFFICE.

HENRY L. CAKE, OF POTTSVILLE, PENNSYLVANIA.

COAL-SCREEN.

Specification of Letters Patent No. 26,890, dated January 24, 1860.

To all whom it may concern:

Be it known that I, HENRY L. CAKE, of Pottsville, in the county of Schuylkill and State of Pennsylvania, have invented a new and useful Improvement in Cast-Metal Coal- Screens; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure l, is a face view of a section of a coal screen constructed according to my invention. Fig. 2, a section of ditto, taken in the line as, oc, Fig. 1.

Similar letters of reference indicate corresponding parts in the two figures.

The object of this invention is to obviate the difficulty hitherto attending the employment and use of cast iron coa-l screens, to wit: the large mass of metal required in proportion to t-he size of the meshes of the screen and the consequent liability of the same to choke or clog. Cast iron screens are of course much cheaper than the woven wire ones, and would be universally adopted if it were not for the above mentioned ditliculty which confines their use to those provided with large meshes.

The invention consists in having the screen formed' with one of its two series of bars broken or staggering as it is technically termed, that is to say, intersecting their cross bars, or bars of the other series, at such points that the row of staggering bars between two of the unbroken or continuous ones, will be in line with the centers of the spaces between its adjoining rows; thereby forming meshes in one direction of the screen that are consecutively out of line and alternately in line with each other, as hereinafter fully described.

To enable those skilled in the art to fully understand and construct my invention, I will proceed to describe it.

A, represents the continuous or unbroken parallel bars of a screen having a parallel position with each other and formed at a suitable distance apart according to the size of the mesh.

B, represents the broken or staggering bars which are short extending only across the spaces between the continuous bars A, each row of bars B, intersecting the continuous bars A, at points in line with the centers of the spaces formed by its adjoining bars, as plainly shown in Fig. l. This arrangement of the two series of bars A, B, causes the meshes a, formed by them to be in one direction, consequently out of line and alternately out of line and alternately in line with each other. At the points of intersection of the bars A, B, projecting spurs Z), are formed. By this arrangement the screen is prevented from choking or clogging; the staggering bars B, cause a greater agitation of the coal on the screen as it is operated, as the coal cannot follow and pass away on the bars B, as it does when said bars are continuous. The comparatively heavy cast iron bars A, B, are therefore compensated for by arranging them as shown and thereby facilitating the passage of the coal through the meshes.

This invention is applicable to rotary cylindrical screens, and to the plain reciprocating ones. It is more especially designated however for operation on a large scale, the screens being of cylindrical form. It has been practically tested and operates well. The screens are cast in the usual way, molds being formed in sand from patterns.

I would remark that although the meshes are represented as being square in Fig. l.

they may be of diamond or other form and the same principle of construction carried out.

I do not claim the spurs b, as they have been previously used; but,

I do claim as new and desire to secure by Letters Patcnt- Casting the screen with broken or staggering bars B, and continuous bars A, substantially as and for the purpose set forth.

, HENRY L. CAKE. Witnesses SAML. STUNTZINGER, SAML. GARRETr. 

